1. Field of the Invention
The present invention relates to a communication apparatus capable of selectively communicating data and speech through a single communication line.
2. Related Background Art
A facsimile apparatus is known as an apparatus of this type. In a prior art facsimile apparatus, in order to selectively use a single telephone line for facsimile communication and speech communication, when a signal received from the line is a facsimile signal, it is determined that a sending station is a facsimile apparatus and the facsimile communication is started. Such an apparatus is described in U.S. Pat. No. 5,019,840 and U.S. Pat. No. 4,800,439.
A service to allocate a plurality of telephone numbers to one telephone line and send out call signals corresponding to the respective telephone numbers (e.g. call signals having different cadences) by an exchange is known. A facsimile apparatus which utilizes this service while assigning a telephone number for speech communication and a telephone number for facsimile communication and identifying call signals for the facsimile apparatus to select the facsimile communication or the speech communication also is known.
On the other hand, data communication between computers and image data communication by a facsimile apparatus have recently been conducted through a public telephone line and communication with various types of modems has been conducted. A modem for computer data communication and a modem for a facsimile apparatus are incompatible and cannot communicate with each other. Thus, where communication is to be conducted through a telephone line, it is required to identify the type of terminal of a destination station when a line is connected with the destination station, and a new communication is to be applied to achieve the communication.
The prior art facsimile apparatus merely has independent functions to switch the facsimile communication and the speech communication and merely utilizes those functions independently. Thus, the facsmile apparatus may not properly switch the facsimile communication and the speech communication for the calls from various types of facsimile apparatus as above mentioned or telephone sets.